The present invention relates generally to a torque motor, and more particularly to a hiding structure for positioning signal conversion mechanism of a torque motor.
A torque motor is able to output greater start torque and has the characteristic of suspension. In a restrained state within the rotational speed-torque characteristic region or when operating at low speed, the torque motor can still keep a stable torque. Therefore, all kinds of torque motors have been widely applied in various fields including semiconductor mechanics, machining tools and positioning and transmission components of detection tables that necessitate constant tension rolling, restrained operation, static torque operation, etc.
However, the torque motor can simply output power, while failing to control the magnitude of the output power itself. Therefore, a motor driver is an important controlling means for the motor. In the modern industrial environment, motor controlling system has been developed from the early-stage analog type into the current digital type. By means of digital signal processing technique, the problems such as bias voltage, component aging and high liability to environmental interference that exist in the analog-type motor controlling system are avoided. Accordingly, the motor controlling system can be more flexibly and conveniently used.
However, the signal and magnetic flux generated by the motor are both bipolar. Therefore, the intermediate circuit must be constituted of analog components for converting voltage level. That is, the feedback analog signal generated by the motor must be first converted into digital signal by means of an analog-to-digital converter. The digital signal is then provided for the driver to process so as to control the voltage and current applied to the motor, whereby the motor can output power as desired.
In the conventional motor controlling system, the analog-to-digital converter is an independent component arranged outside the torque motor. Therefore, when the positioning signal detected inside the torque motor is output to the converter outside the torque motor in the form of analog signal, the signal is transmitted in a longer path. Accordingly, the analog signal is likely to be distorted. In this case, the digital signal will give incorrect data to the driver. This will result in misoperation of the torque motor to affect manufacturing process.